EuroSCORE II had better predictive discrimination for operative mortality than EuroSCORE I, which greatly overestimated this risk. EuroSCORE II fared well compared with the STS risk score. The inclusive nature of EuroSCORE II for numerous procedures provides more flexibility than the STS score for complex procedures. EuroSCORE II should be considered for calculating risk score for complex cardiac surgical patients.

The Cox maze III/IV procedure can be performed safely and effectively in patients with higher operative risk, who fare well when compared with lower-risk patients. The Cox maze III/IV procedure should be considered carefully in patients with a significant history of atrial fibrillation.

In our center, 76% of patients undergoing mitral valve or mitral valve+tricuspid valve surgery experiencing AF underwent concomitant Cox-maze procedure, which is considerably higher than the national average. No increased morbidity was associated with the Cox-maze procedure with the benefit of very low thromboembolic rate. These results suggest the need for performance-based education for AF surgical ablation to achieve optimal outcomes.

In patients with a routine postoperative course, older age was associated with more postoperative blood transfusion. Older age was also predictive of longer length of stay and poorer survival, even after accounting for clinical factors. Continued study into effects of transfusion, particularly in the elderly, should be directed toward hospital transfusion protocols to optimize perioperative care.

The STS risk model was reliably predictive of short and extended LOS but did not allow prediction of exact LOS in days. Accounting for potentially modifiable clinical variables, such as low hematocrit and blood transfusion, especially in elective patients, should lead to shorter LOS, higher satisfaction, and reduced financial burden.